Throw exceptions when attempts are made to use localStorage in packaged apps.

chrome/renderer/resources/extensions/platform_app.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Returns a function that throws a 'not available' exception when called.
  *
  * @param {string} messagePrefix text to prepend to the exception message.
  */
-function generateStub(messagePrefix) {
+function generateStub(messagePrefix, opt_messageSuffix) {
   return function() {
-    throw messagePrefix + ' is not available in packaged apps.';
+    var message = messagePrefix + ' is not available in packaged apps.';
+    if (opt_messageSuffix) message = message + ' ' + opt_messageSuffix;
+    throw message;
   };
 }
 
 /**
  * Replaces the given methods of the passed in object with stubs that throw
  * 'not available' exceptions when called.
  *
  * @param {Object} object The object whose methods to stub out. The prototype
  *     is preferred.
  * @param {string} objectName The display name to use in the error message
@@ skipping 11 matching lines @@
  * Replaces the given properties of the passed in object with stubs that throw
  * 'not available' exceptions when gotten.
  *
  * @param {Object} object The object whose properties to stub out. The prototype
  *     is preferred.
  * @param {string} objectName The display name to use in the error message
  *     thrown by the stub (this is the name that the object is commonly referred
  *     to by web developers, e.g. "document" instead of "HTMLDocument").
  * @param {Array.<string>} propertyNames property names
  */
-function stubOutGetters(object, objectName, propertyNames) {
+function stubOutGetters(object, objectName, propertyNames, opt_messageSuffix) {
   propertyNames.forEach(function(propertyName) {
     object.__defineGetter__(
-        propertyName, generateStub(objectName + '.' + propertyName));
+        propertyName, generateStub(
+            objectName + '.' + propertyName, opt_messageSuffix));
   });
 }
 
 // Disable document.open|close|write|etc.
 stubOutMethods(HTMLDocument.prototype, 'document',
     ['open', 'clear', 'close', 'write', 'writeln']);
 
 // Deprecated document properties from
 // https://developer.mozilla.org/en/DOM/document.
 stubOutGetters(document, 'document',
@@ skipping 10 matching lines @@
 
 // Disable modal dialogs. Shell windows disable these anyway, but it's nice to
 // warn.
 stubOutMethods(Window.prototype, 'window', ['alert', 'confirm', 'prompt']);
 
 // Disable window.*bar.
 stubOutGetters(window, 'window',
     ['locationbar', 'menubar', 'personalbar', 'scrollbars', 'statusbar',
     'toolbar']);
 
+// Disable window.localStorage.
+stubOutGetters(window, 'window',
+    ['localStorage'],
+    'Use chrome.storage.local instead.');
+
 // Disable onunload, onbeforeunload.
 Window.prototype.__defineSetter__(
     'onbeforeunload', generateStub('onbeforeunload'));
 Window.prototype.__defineSetter__('onunload', generateStub('onunload'));
 var windowAddEventListener = Window.prototype.addEventListener;
 Window.prototype.addEventListener = function(type) {
   if (type === 'unload' || type === 'beforeunload')
     generateStub(type)();
   else
     return windowAddEventListener.apply(window, arguments);
 };